Bridging switch for testing series light circuits



R. 'r. WOOD BRIDGING SWITCH FOR TESTING SERIES LIGHT CIRCUITS April 13, 1948.

Filed Dec. 16, 1946 n-pawik menu/r Patented Apr. 13, 1948 UNITED STATES PATENT OFFICE Bamcme swrrcnm sgme seams LIGHT Richard T. Wood, Memphis, Tenn. Application December 16, 1946, Serial No. 716,504

2 Claims. (Cl. 200-159) This invention relates to normally open switches for testing series light circuits, which switches are installed respectively across the branches leading in circuit through the various lights of a multiple light circuit and which, where a light has burned .out and the circuit been thereby interrupted, may be successively closed,-bridging the branch circuits in succession until the faulty light is located and replaced.

It further relates to such switch for ornamental lighting circuits, as those used on Christmas trees, in which the switches are of type and materials to augment the ornamental eilects of the lighting.

In Christmas tree lighting, much use is made of groups of ornamental light bulbs, some seven or eight usually being used, which are wired-tin eries circuit to reduce the voltage of the individual bulbs or for other reasons. When one of these bulbs burns out, as they often do, the circuit is interrupted and all are dead until the faulty one is located and replaced. This is usually done by successively trying a fresh bulb in each socket in succession until the faulty one is reached and replaced and all burn again, or by using a bridging tool which ifit so happens that it can be found when it is needed, tends to damage necessarily exposed portions of the insulation, sometimes dangerously.

Among the objects of the present invention are:

To provide test switches biased open, which respectively are mounted on the branches of a series light circuit in adjacency to the bulb sockets, and in testing are successively closed to bridge the branch circuits and bypass the bulbs.

To provide simple and eflicient switches which may be applied to insulated wire circuits without removing the insulation from the wires or effecting substantial damage thereto.

To provide switches for ornamental light circuits, which switches are of ornamental configuration and have light reflecting surfaces;

And generally to simplify and improve the construction, configuration, and appearance of ornamental lighting circuits and switches therefor.

The means by which the foregoing and other objects are accomplished and the manner of their accomplishment will readily be understood from bulbs, the central switch of the group being shown relatively much enlarged.

Fig. 2 is a sectional plan of the switch taken on the line 11-11 of Fig. 1. I

Fig. 3 is an elevational view of the inner face of one of the halves of the switch housing looking in the direction of the arrow III of Fig. 2.

Fig. 4 is a similar view of the complementary half of the housing looking oppositely in the direction of the arrow IV of Fig. 2.

Fig. 5 is a similarly enlarged perspective view of an ornamental configuration of the switch housings Referring now to the drawing in which the various parts are indicated by numerals:

I I is a circuit leading from a suitable power circuit iii in series through a plurality of ornamental light bulbs l5. Switches l1 and I9 are mounted across the circuit, preferably in adjacency to the sockets 2| of these bulbs, the switch l9 being of identity with the switches l1, but being shown much enlarged for purposes of illustration and separately identified for easier reference.

Each switch comprises a housing made in complementary halves 23 and 25 secured together as by screws 21. These halves are of insulating material and for appearance are preferably of lucent plastic, either clear and transparent or brightly colored, and further such material is preferably one which will take a high polish and tend to reflect light. The halves 23 and 25 are the following specification on reference to the accompanying drawings, in which:

Fig. 1 is a diagrammatic view of a lighting circuit showing in elevation a plurality of bulbs in series and switches respectively related to the 68 channelled to provide grooves 23A, 23B; 25A, 25B which are complementary and adapted to receive 7 the insulated wires IIA, IIB of the circuit, the wires being clamped in these grooves when the halves are secured together by screws 21.

Embedded in the half 23 are contact members 29, 3|, here shown U-shaped, which have sharpened ends 29A, 31A extending into the grooves 23A, 233 to penetrate the insulation of the wires HA, 3 and electrically contact the wires themselves, and have opposite ends 293, SIB which extend slightly above the surface of the half between the grooves and the center of the half. The half 23 is also provided with a central well 33 in which is disposed a compression spring coil 35.

The half 25 is provided with a central chamber overlying the ends 293 and (B of the contacts 29 and 3| and a concentric aperture 39leading thereinto, to respectively receive a bridge member 4| which is held in raised position by the spring 35, and an attached button 43 for depressing the member ll into circuit closing engagernent 'with the contacts 29, 3|. An unnumbered guide stem may extend from the bridge member 4| within the coil spring 35.

In Fig. 5, the housing halves 23A, 25A have their corners chamfered to provide additional bulb circuits.

In use, should any bulb bum out'all the lights go out without indication of which is faulty. The

buttons 43 of the switches are successively depressed, closing the switches successively and bridging the circuits without efiect until the faulty bulb is reached and its circuit is bridged, completing the entire circuit and restoring the other lights. The faulty bulb is removed and a new one installed, restoring the circuit and lighting all the bulbs.

I claim:

1. A switch for a lighting circuitremploying insulated wires, said switch including matinghalves of insulating material forming a substantially cubical insulating housing having parallel channelways therethrough along the mating surfaces of said halves for the reception of said insulated wires, spaced U-shaped contacts embedded in one of said halves, saidcontacts having sharpened points respectively extending intosaid channelways to a depth penetrating the insulation of said wires, and into electrical contact therewith, and oppositely terminating, beyond the mating surface of said half, in contact seats.

said half beingchambered between said contacts to form a well, the other said half being interiorly chambered between said channelways and around said seats, and having an entrance opening into the top of said chamber, a member adapted to bridge between said seats disposed in said chamber, a spring in said wel1 urging said bridge away from contact with said seats, and a button oppositely bearing on said-member and extending through said entrance opening to an accessible position beyond said housing.

2. A switch in accordance with claim 1, in which said housing is of lucent material and has highly polished exterior reflecting surfaces.

- RICHARD T. WOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Meuer Aug. 8, 1933 

